The invention set forth in this specification pertains to new and improved liquid mixing devices or mixers. More specifically it is primarily directed towards liquid mixing devices which can be utilized for a variety of different purposes such as mixing various types of bar drinks, milkshakes, breakfast drinks and the like but which can also be utilized for such functions as mixing various types of batters, beating eggs, whipping cream and the like. Liquid mixers which are closely related to the mixers of the present invention are sometimes generically classified as beverage mixers.
Such beverage mixers have been commonly constructed so as to include a vertically extending support holding a housing generally above and forwardly from the support. In such a mixer normally an electric motor is mounted within the housing so that its shaft extends generally vertically. Although in some cases the shaft of the motor is constructed so as to extend downwardly from the motor it is common in mixers of the type indicated to mechanically secure a downwardly extending shaft to the motor shaft. In either case a mixing structure or element for causing fluid motion is normally located on the extremity of a shaft below the motor. When a common beverage mixer as noted is used a container or vessel such as a glass or the like containing the ingredients to be mixed with the mixer is located generally around the structure or element for causing fluid movement.
A number of different mixing elements or structures have been commonly utilized in such mixers for the purposes of causing fluid movement of ingredients and of mixing air with such ingredients. It is not considered that an understanding of the present invention requires a detailed discussion of all prior mixing structures or elements. A wide variety of different types of fluted disks, propellers and the like have been commonly used as such elements or structures. All of such prior fluid movement elements or structures are considered to be utilitarian to at least a degree. However, problems have been encountered with the use of beverage mixers as herein indicated constructed so as to utilize such common fluid movement structures and elements.
One type of problem concerns the possibility of damage to the vessel or container employed with such a beverage mixer to contain the liquid or liquid mixture. Normally after the liquid mixture has been prepared using the complete mixer the container or vessel is removed from the mixer after the motor is shut off but while the mixing element or structure is still rotating. When this occurs there is a significant danger of damage occurring as a result of contact between the mixing element or structure and the container or vessel. This is particularly the case when such a container or vessel is made of glass.
Another problem which has been encountered during the use of beverage mixers as equipped with common mixing structures or elements concerns the movement of the liquid within such a vessel or container as the motor is operated. Frequently what may be regarded as a form of resonance is set up within such a liquid or liquid mixture which causes the upper level of the liquid or liquid mixture to continuously rise and fall within the container or vessel. Although in a sense at times this can be advantageous as promoting contact with the ambient air it can also be disadvantageous because of the possibility of the liquid spilling over the upper edge of the container or vessel. It is possible to enter into a discussion as to whether or not such up and down surging of the liquid does or does not influence the effectiveness of the mixing action obtained.
A number of other matters concerning the operation of beverage mixers of the type broadly indicated equipped with various types of mixing elements or structures could be discussed in this specification. Also this specification could be encumbered by detailed discussion as to the relative merits of prior types of mixing or fluid movement stirring and similar devices as have been employed in such beverage mixers. It is not considered that an understanding of it requires such a detailed discussion. It is considered, however, that an understanding of the invention set forth in this specification requires an understanding of the fact that beverage mixers of the type indicated in the preceding discussion and the mixing elements or structures used as parts of such mixers have been of such a character as to make it desirable to improve such structures.